Birds

Question 1

What does anisodactyl refer to?

Answer 1

Finger oreintation

Question 2

Endothermy i.e. the ability to maintain a high core body temperature over a broad range of ambient heat by producing at rest, what kind of heat?

Answer 2

endogenous heat

Question 3

Birds tend to have ______ hearts than mammals (relative to body size and mass)

Answer 3

larger

Question 4

The avian eye is large relative to the size of the head and brain. They have 3 eyelids. What are they?

How many photoreceptors are in an avian eye?

Answer 4

One upper, one lower & nictitating membrane

4 photoreceptors

Question 5

What is grating acuity?

Answer 5

The smallest distance between single elements of periodical pattern that is just resolved (and is reported as cycles per degree [cpd])

Question 6

What clade of bird is flightless?

Answer 6

PALAEOGNATHAE

Question 7

What is meant by pneumatic?

Answer 7

Hollow, thin walled, air-filled bones; marrow cavities of long bones empty

Light but very strong

Question 8

What are the two major flight muscles? What do they do?

Answer 8

PECTORALIS –> Contracts, wing pulled down

SUPRACORACOIDEUS –> contracts, wing pulled up

Question 9

Feathers attached to the “hand” are ________ and feathers attached to the “arm” are _______

Answer 9

Primaries

Secondaries

Question 10

Forward propulsion is caused by…

Answer 10

Primaries on manus (hand)

Question 11

Vertical lift is caused by…

Answer 11

Secondaries on ulna (arm)

Question 12

Reduction of drag is caused by…

Answer 12

Alula on digit II

Coverts on ulna

Rectrices (tail) on pygostyle

Question 13

At a high speed…

Answer 13

there is a low angle of attack, low drag

Question 14

At a low speed…

Answer 14

There is an increasing angle of attack, but high drag

Question 15

Frictional drag is caused by…

Answer 15

air resistance

Question 16

Induced drag is caused by…

Answer 16

the formation of vortices at wingtips when the air flow separated from the airfoil

Question 17

How are birds morphologically adapted to minimise drag?

Answer 17

• Lack of external ears
• Feet tucked in
• Feathers (alula, coverts, tail)
• Wing shape

STREAMLINING

Question 18

In flight, if speed is high, how will the following be affected:

Drag?
Manoeuvrability?
Lift?
Flapping rate?

Answer 18

High speed =

low drag
low manoeuvrability
high lift
low flapping rates

Question 19

In flight, if speed is low, how will the following be affected:

Drag?
Manoeuvrability?
Lift?
Flapping rate?

Answer 19

Low speed =

high drag
high manoeuvrability
low lift
high flapping rates

Question 20

Wing loading = ?

Answer 20

Wing loading - mass/wing area (g/cm^2)

Question 21

Name at least 3 functions of feathers

Answer 21

• Flight (primaries, secondaries, tail feathers)
• Insulation (down feathers, semi-plumes, filoplume)
• Waterproofing (contour, powder down)
• Display (tail feathers, contour feathers)
• Camouflage (contour feathers)
• Eye and nostril protections (bristles)

Question 22

What are the 6 commonly recognised types of feathers?

Briefly describe

Answer 22

1. Vaned or contour: form the outer coverings of a birds body, including primaries, secondaries & tail feathers
2. Down: layer of loosely structured feathers beneath contour feathers which help to trap air near the bird’s body for warmth
3. Semiplume: Loose and fluffy feathers similar to down feather; provides body insulation and increases the buoyancy of water birds
4. Filoplume: Small hair-like feathers with a few barbs at the tip of the shaft; they occur among the contour feathers
5. Bristle: Modified, vaneless contour feathers with a few bards at the base on a small, stiff rachis. They can occur around the eyes, nostrils, and in flying insect-catching birds around the mouth, called rictal bristles
6. Powder down: Feathers that grow continuously and are never moulted. The barbs at their tips constantly disintegrate into a fine talc-like, water-resistant powder. Often abundant in birds that lack preen glands

Question 23

What is migration?

Answer 23

2 way movement between breeding and wintering areas.

Question 24

In mountainous regions of the world, many species of bird exhibit altitudinal migration, ________ at higher altitudes

Answer 24

breeding

Question 25

Name at least three challenges of migration

Answer 25

• Precise timing of physiological events; internal clock (circannual rhythm); External factors (day length)
• Endurance performance; storage of large amounts of fat
• Orientation/navigation

Question 26

How do some birds orientate during migration?

Answer 26

• Magnetic Compass Orientation (eye & beak)
• Solar orientation
• Visual landmarks
• Star pattern orientation
• Multiple Orientation mechanisms

Question 27

Birds are strictly ________

Answer 27

oviparous

Question 28

All birds incubate their eggs except a small group of birds in the Megapodes family. What kind of chick development is this?

Answer 28

Superprecocial

Question 29

What is meant by social monogamy?

Answer 29

One male and one female cooperate to raise a brood of young

Question 30

What is meant by polygyny?

Answer 30

A male bird breeds with more than one female

Question 31

What is meant by polyandry?

Answer 31

A female bird abandons her eggs to breed with several males; the incubation and parental care is left to the male

Question 32

What is meant by lekking?

Answer 32

Cluster of males to attack females; males provide nothing but genes/sperm

Question 33

In polyandry, which gender is more colourful? What is this known as?

Answer 33

Females are more colourful

REVERSED SEXUAL SELECTION